yo,
See if this is it Hanging vertically to right of Red MSD Coil, pic by Booba5185
Next is to try a Self Test for Diagnostic Trouble Codes (DTC)s by my pal, BroncoJoe19 @
http://broncozone.com/topic/14269-code-reader/page__pid__74587__mode__threaded
The engine temperature must be greater than 50° F for the Key On Engine Off (KOEO) Self-Test and greater than 180° F for the Key On Engine Running (KOER) Self-Test.
Run it around to heat the engine up and shift thru all gears incl Reverse. Then turn off all accessories/lights, etc.
Make sure A/C is off and transmission is in Park (automatic) or in Neutral for a Manual & release clutch.
Do Key On Engine Off (KOEO) portion first.
Look Codes up in my broncolinks.com site using the new Search function.
And Post em here according to:
KOEO
&
KOER
--
and go through this TFI Troubleshooting Worksheet; miesk5 Note; this is the Grey Module
Source: by SeattleFSB (Seattle FSB) at SuperMotors.net
Wiring Diagram in 87-91 (from Factory Manual and the Ford Electrical & Vacuum Troubleshooting Manual (EVTM) Source: by Broncobill78 (Dave) at Ford Bronco Zone Forums
see the Ignition Diagnostic Monitor (IDM) Resistor, 22K Ohm w/DG/Y to EEC IV and W/LB from Ignition Coil Tach terminal
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Troubleshooting Tips, Distributor-Mounted; "...1. Verify charging system operation; specifically, charging voltage. 2. Verify ignition system operation; specifically, there are no open or disconnected plug wires. 3. Remove distributor cap and inspect connections where TFI module hooks to the Hall Effect Switch connector. If there is any sign of deterioration at the connector, the Hall Effect pickup must be replaced. Crankcase vapors are forced into the distributor due to excessive crankcase pressure due to a worn engine or an improperly maintained PCV system. The crankcase vapors cause deterioration of the insulation around the connectors causing the module to short out..."
Source: by napaechlin.com
Hazard Stumble TSB 88-16-16 for 87-88 Bronco & F Series; "...ISSUE: An engine miss or stumble when the headlamp hi-beams, hazard, stop or turn signals are turned "ON/OFF" may be caused by a voltage spike. A voltage spike may be induced into the EEC IV ignition system and read by the EEC IV processor as a PIP signal. This creates false timing information resulting in the miss or stumble. Vehicles that are used to pull trailers (electrical brake equipped) may have similar symptoms. ACTION: To correct this, install a ground strap between the battery negative (-) terminal and the radiator support bracket using existing attaching hardware or a #10 sheet metal *****..."